1. Field of the Invention
This invention relates to an orthotic device for bracing a foot, and in particular, to an orthotic device having a formable body which can be wrapped tightly enough around a foot to create hydrostatic pressure of the soft tissue of the foot within the walls of the orthotic device.
2. Discussion of the Prior Art
Pronation in the pediatric population has long been recognized as a significant problem. In order to address this issue, it is necessary to distinguish the difference between flat foot and a pronated foot. Although the average person may not be able to differentiate between the two, the divergence is quite clear.
A flat foot is simply a medial longitudinal arch (the main arch on the instep of the foot) which has very little curvature or vault to it. In this case, the arch will continue to maintain the shape both in weight bearing and in non-weight bearing positions.
A pronated foot, which is often mistakenly referred to as a flat foot, may very well have a nicely curved or bow-shaped medial longitudinal arch in non-weight bearing circumstances, but when the individual with a pronated foot stands or otherwise bears weight the foot flattens out. This falling or collapsing of the medial longitudinal arch is the one of the components of the pronated foot. Pronation can best be described as combinations of the heel rolling into a valgus position wherein the lower aspect of the heel angles away from the center of the body causing the inner ankles to shift in towards each other. The valgus position is worsened as the full weight of the body is brought down upon the heel. This in turn causes the mid foot to evert or flatten across the medial longitudinal arch. The end result is an abduction or shifting away of the foot from the center or midline of the body.
Pronation of the foot can cause many problems both intrinsic and extrinsic to the foot. Intrinsically, a significant amount of stress is placed on the subtalar joint (the articulation of the calcaneus talus) when the calcaneus heel rolls into a valgus position. As the mid foot everts or flattens weight bearing of the metatarsal heads is changed, creating not only stress on the joints of the mid foot, but also an undue amount of weight to be born through the lateral (outside) aspect of the foot. Extrinsically this pronation changes the angle at which the tibia (shin bone) is positioned during weight bearing causing a great deal of stress on the knee and hip joints.
Children deal with and perceive this type of stress on the joints as a fatigue and will tend to spend more time sitting instead of standing and playing on their feet. The improper positioning of the bones of the foot and ankle also serve to create a sense of instability in younger children, resulting in poor balance and poor development of upright motor skills. Hyper pronation may be observed in very young children and in some cases may be treated with casts. Most cases though, go undetected and untreated until the patient bears weight on the foot and wear shoes. Early recognition and detection of hyper pronation and control thereof is essential to allow a child with pronation to participate fully in normal activities and to preclude stress in the knees and hip joints which may cause problems as the child develops into an adult.
Uncorrected pronation can lead to the development of problems in adults intrinsic to the foot such as heel spurs, bunions, and hammer toes, as well as symptoms extrinsic to the foot such as knee pain and low back pain.
Over the years many devices have been established and marketed to combat this problem. Various types of braces, shoes and shoe supports have been developed. Shoe modifications as well as heel modifications, such as the Thomas Heel, have been utilized for years but have been relatively ineffective. An inner sole orthotic device for treating pronation is disclosed in U.S. Pat. No 5,174,052 to Schoenhaus, et al., incorporated herein by reference, but an inner sole device alone cannot provide sufficient support for children experiencing severe pronation. In addition, many devices to treat pronation are heavy, awkward, or inhibit the walking and other activities of the wearer.
Therefore, it is an object of the invention to provide a new and improved device of treating pronation, and more particularly a device particularly suited for treating the pediatric population weighing less than 85 pounds.
It is a further object of the invention to provide a device for treating pronation that is light weight and effective.
An additional object of the invention is to provide a device for treating pronation that is formable and can create hydrostatic pressure within the soft tissue of the foot to provide proper support and development.
A feature of the invention is to provide an orthotic for correction of foot pronation and a method to fabricate the foot orthotic. The orthotic includes a thin formable body having pliable medial and lateral side walls and a pliable bottom, and a securing mechanism to draw the side walls about a foot so as to create a hydrostatic pressure of the soft tissue of the foot within the orthotic.
Another feature of the invention is to have the securing mechanism include hook and loop straps attached to the pliable body and looping rings attached to the pliable body for wrapping the straps therethrough.
Also, a feature of the invention is to have the pliable body include vacuumed formed plastic wherein the plastic is chosen form the group consisting essentially of polypropylene, polyethylene or copolymer.
It is a further feature of the invention to include a heel post attached to the bottom of the foot orthotic to provide stability for standing or walking and to have the heel post formed from a semi circular piece of material chosen from the group consisting essentially of polypropylene, polyethylene, or copolymer.
An additional feature of the invention is to have the pliable body shaped to rise above the ankles of a user and to dip down posteriorly to the top of the user""s heel. The foot orthotic is also designed to wrap over the dorsum of the foot on both the medial and lateral sides thereof.
Another feature of the invention is that a narrow gap is defined by the pliable body between the medial and lateral walls thereof as said pliable body is wrapped about the foot.
It is also a feature of the invention that the pliable body extends medially just proximal to but not encompassing the first metatarsal head of the foot and laterally just distal to and encompassing the fifth metatarsal head of the foot.
Lastly, it is a feature of the invention to provide a foot orthotic that may be fabricated using a cast of the foot to receive the orthotic or by taking selective measurements of the foot to receive the orthotic and choosing a positive mold from among a number of preexisting molds in accordance with the measurements.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described herinafter and which will form the subject matter of the claims appended hereto.